There are many external and internal factors that reduce the lifespan, cause spoilage and pollution in dried fruits. Food spoilage is generally divided into 3 categories: physical, chemical and biological. Spoilage causes adverse changes in dried fruit. Dry fruit spoilage can be caused by pests, entry of microorganisms and internal and external factors. The spoilage of dried fruit and pathogenic agents cause a drop in the quality and nutritional value of the product and make it unusable. It also changes the smell, color, taste and taste of dried fruit.
Physical, chemical and biological methods are used to prevent the spoilage of dried fruit and increase the life of the product. Physical methods include:
- Preventing pests from entering
- Destroying pests using radiation
- Separation of clean products from non-clean products
- Do not freeze infected dried fruit
- Addition of ascorbic acid
- Immersion in sugar syrup and…
Chemical methods include:
- Removing and killing pests and microorganisms using chemical methods and substances
- Use of organic acids (benzoic acid, propionic acid)
- Sorbic acid and sorbates
- Nitrites and nitrates
- Sulfites and metasulfites
- Formaldehydes and…
- Biological methods include inactivating enzymes in dried fruit.
Factors causing spoilage in dried fruit
Ambient humidity
One of the elements for the growth of microorganisms is the presence of moisture in the environment. The free water in the environment is more easily and better than the water in the building of the food material, and the spoilage accelerates.
temperature
The suitable temperature for the growth of microorganisms in dried fruit is generally ambient temperature and higher. Therefore, lowering the temperature during product storage and sale can help increase the product’s life and prevent its spoilage.
Ambient air composition
Ambient air includes oxygen, nitrogen, hydrogen, carbon dioxide, etc. gases. Aerobic microorganisms need oxygen for their growth, and the presence of gases can increase their growth and increase the rate of food spoilage. Nitrogen is an inert gas and in the packaging of many products, it reduces or eliminates the presence of oxygen and adds nitrogen. One of the ways to increase product life is to use MAP and CAP packaging technology, which is based on changing the ratio of the presence of gases in the vicinity of a food item.
the light
Many microorganisms use sunlight to provide their energy for survival, and this is not a good factor for food preservation. Also, some wavelengths of light that contain a higher amount of energy, such as ultraviolet waves, cause changes in the structure of food and will cause health risks.
Storage time
The duration of growth of microorganisms is different, therefore the different times of food spoilage during their growth and reproduction are different. Any factor that can prevent the growth and reproduction of microorganisms can increase the life of the product and prevent the spoilage of that food.
Moisture percentage in dried fruit
The fruit consists of two parts, aqueous and non-aqueous and solid. The amount of moisture in each fruit is different from another. The higher the amount of moisture in food, the more suitable the conditions are for the growth of microorganisms, and as a result, the rate of food spoilage increases. Due to its nature, dried fruit loses a large part of its moisture during the drying stage, so the lower the moisture content and the drier the fruit, the longer the useful life of the product.
microorganisms
One of the most important factors of food spoilage is the existence of microorganisms. Microorganisms include a wide range of microscopic organisms, including bacteria, mold, yeast, fungi, algae, protozoa, etc., and bacteria are the most important of them because they have the highest level of adaptation and reproduction in the environment. One of the ways to fight dry fruit corruption is to prevent their entry and reproduction in dry fruit. By washing and disinfecting the fruits before entering the drying process, as well as using physical processes such as irradiating the dried fruit, all microorganisms and pests can be eliminated and spoilage can be minimized.
Natural enzymes in dried fruit
Enzymes act as catalysts for chemical reactions in dried fruit and speed up the spoilage process. Normally, the natural enzymes in the fruit are located in tissues and cell layers that cannot participate in the reaction. If the fruit is cut and the enzymes are released, as well as contact with the air, the rate of spoilage increases. Deactivating biological enzymes in fruit is one of the ways to increase the life of dried fruit.
After cutting, the fruits should be dried quickly and their contact with the ambient air should be avoided. After drying, the fruits should be packed and placed away from moisture and air.
pests
Primary insects and pests that can enter the production process by fresh fruit and secondary pests that can contaminate the product after the drying process are other factors of dry fruit spoilage. To prevent this from happening, incoming fruits must be thoroughly washed and disinfected. Natural preservatives can also be used to extend their life.
packaging method
Healthy packaging without seams and tears plays a significant role in preventing contamination and spoilage of dry fruits. Dried fruit should be stored in a dry and cool place away from the ambient air to keep it healthy for a longer period of time.
How to determine the presence of corruption in dried fruit?
If we want to determine the presence or absence of food spoilage in dried fruit in general and without using laboratory equipment, the following factors should be checked:
- Visible signs: obvious mold, fluid secretion, unexpected changes in color
- Bad smell of the product
- If the texture of the product becomes plastic and flexible and loses its dry and crispy state.
- If the taste and flavor of the dried fruit has changed and it does not have the fresh and natural taste of the corresponding fruit, it indicates corruption and loss of product quality.
In addition to the correct and principled conditions for the production and storage of dried fruit according to valid standards until the moment of delivery of the goods, the consumer must also take into account the above items in maintaining the quality and optimal storage of dried fruit in order to prevent corruption until the expiration date.